i kind of ran into the same problem on my xcr. the carbs hit the motor mount plates because the engine is mounted at an angle the lowers the engine a little and leans it back more. i cut the motor mount plate but was considering turning the intake boots upside down.

if i were you i would try to keep the engine mounted back, putting that much weight up front probably wouldn't feel too good. maybe mock up some shims from washers, grind them or file them with an angle so they will sit flat against the engine and in between the engine and plate. would have to be pretty precise for it to be the same at all 2points and 2 more points so 4 would have to be made. or as others said use a different carb boot, i think that's probably the best and least effort approach.

Bowls aren't designed to be mounted at much of an angle , it'll run just fine in the garage and WO but the mid and bottom will have you chasing random gremlins at the other end of a tow rope trying to figure out if it's a seal , needles , fuel pump or electrical .

Is there enough room to put a sleeve over the jack shaft ? and run angled pods ?

Man thats A tight fit. My 800 twin is snug as hell in that chassis. I recently put angles UNI pod filters on mIne, much better air flow thaN the k&n style filters. Clears the jack shaft by about 1/4 inch